A measuring device and method for rapidly detecting the oxygen content of a vial

Abstract

The application discloses a kind of measuring device and method for quickly detecting oxygen content of penicillin bottle, it is related to gas spectrum measurement field, including external optical path system, external optical path system includes DFB laser, beam splitter, plane mirror and fiber coupling beam splitter, DFB laser is sequentially connected with frequency-locked system by beam splitter and plane mirror light transmission;DFB laser is coupled with fiber coupling beam splitter by beam splitter, fiber coupling beam splitter is respectively connected with first detection system, second detection system, third detection system light signal output, computer is respectively connected with first detection system, second detection system and third detection system electrical signal input connection.The application realizes the locking of laser frequency at oxygen absorption peak frequency by frequency-locked system, greatly improves the response rate of detection device;Simultaneously, the simultaneous detection of laser to multiple sample bottles is realized by the mode of fiber coupling, and the detection rate is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas spectrum measurement, in particular to a measuring device and method for rapidly detecting oxygen content of a vial. BACKGROUND

[0002] The vial is a borosilicate glass or sodium cover glass tube injection bottle, and the demand for the vial is huge in the pharmaceutical industry. During the packaging process, factors such as unstable stoppering and capping may cause oxygen to be mixed into the vial, which will directly affect the quality and shelf life of the drug. Therefore, after packaging is completed, the residual oxygen concentration in the bottle needs to be detected to prevent products with excessive residual oxygen from being put into the market.

[0003] At present, most pharmaceutical enterprises adopt the traditional sampling detection method, which is time-consuming, low in precision, and has a high rate of missed detection, and since it is a contact type measurement, it is destructive to the sample. Tunable diode laser absorption spectroscopy (TDLAS) technology has been widely used in trace gas monitoring due to its characteristics of online in-situ measurement, high resolution, high sensitivity, high stability, and fast response speed. Related teams have combined the second harmonic (2f) signal to detect the oxygen content in the vial. However, measuring the oxygen concentration based on the 2f signal requires real-time scanning of the laser and concentration calculation, so how to achieve rapid, high-sensitivity, and accurate detection of the oxygen concentration in the vial is still a problem to be solved in the industry and academia.

[0004] Based on this, a measuring device and method for rapidly detecting the oxygen content of a vial are proposed. SUMMARY

[0005] The present application aims to overcome the above-mentioned problems in the prior art and provide a measuring device and method for rapidly detecting the oxygen content of a vial, which facilitates rapid, high-sensitivity, and accurate detection of the oxygen content of the vial.

[0006] To achieve the above technical purposes and effects, the present application is implemented by the following technical solutions:

[0007] A measuring device for rapidly detecting the oxygen content of a vial, comprising an external optical system, a first detection system, a second detection system, a third detection system, and a computer, wherein the external optical system comprises a DFB laser, a beam splitter, a plane mirror, and a fiber-coupled beam splitter, the DFB laser is optically connected with a frequency locking system in sequence through the beam splitter and the plane mirror;

[0008] The DFB laser is coupled with a fiber coupling beam splitter through a beam splitter, and the fiber coupling beam splitter is connected with a first detection system, a second detection system and a third detection system for optical signal output, respectively.

[0009] Preferably, the frequency locking system comprises a reference gas cell, a photodetector four and a signal acquisition and feedback control system, and the DFB laser sequentially transmits laser between the reference gas cell and the photodetector four through the beam splitter and the plane mirror, and the laser is transmitted to the photodetector four by the reference gas cell, and the output end of the photodetector four is connected with the signal acquisition and feedback control system.

[0010] Based on the above technical features, the laser frequency is locked.

[0011] Preferably, the DFB laser is connected with a driving current source and a temperature control.

[0012] Based on the above technical features, the laser wavelength is continuously tuned.

[0013] Preferably, the signal acquisition and feedback control system comprises a function generation module, a digital demodulation module and a PID module.

[0014] Based on the above technical features, the function generation module is used for modulating the current of the laser, the digital demodulation module is used for generating a 1f signal, and the PID module is used for processing the 1f signal and superimposing a sine signal to realize the locking of the laser frequency.

[0015] Preferably, the first detection system comprises a to-be-detected penicillin bottle one and a photodetector one, the second detection system comprises a to-be-detected penicillin bottle two and a photodetector two, the third detection system comprises a to-be-detected penicillin bottle three and a photodetector three, and the photodetector four, the photodetector one, the photodetector two and the photodetector three all comprise a transimpedance amplification circuit and a low-pass filter.

[0016] Based on the above technical features, the transimpedance amplification circuit is used for amplifying the electrical signal, and the low-pass filter is used for filtering the amplified signal.

[0017] Another technical scheme provided by the application is a detection method for rapidly detecting the oxygen content of a penicillin bottle, comprising the following steps:

[0018] Step 1, turn on the power supply of the DFB laser, adjust the output current and temperature, so that the light frequency is near the oxygen absorption line; the signal acquisition and feedback control system outputs a triangular wave signal and superimposes it to the DFB laser, observes the absorption spectrum collected by the photodetector four, and extracts the current value at the absorption peak;

[0019] Step 2, remove the triangular wave scanning signal, adjust the laser current to the absorption peak, signal acquisition and feedback control system output sine wave superimposed to the DFB laser;

[0020] Step 3, signal acquisition and feedback control system will be carried out by the modulation signal with absorption characteristics of the differential operation, open its PID function, realize the dynamic feedback of the absorption peak current and feedback to the current drive of the laser, realize the frequency locking of the laser at the reference gas absorption peak position;

[0021] Step 4, the oxygen standard gas is put into the detection area, and the four level value Vb of the photodetector under the current condition is measured. The oxygen standard gas with different concentrations is repeatedly measured, and the relationship between the corresponding standard gas oxygen concentration and the photodetector Vb is obtained, and linear fitting is carried out;

[0022] Step 5, the frequency-locked laser is coupled into the fiber-coupled beam splitter, and the laser is distributed to the first detection system, the second detection system and the third detection system respectively;

[0023] Step 6, according to the height of the to-be-detected vial one, the to-be-detected vial two and the to-be-detected vial three, the height of the optical fiber output head is adjusted so that it can pass through the bottle. The empty sample bottle is vacuumized and placed in the detection area. The level values of the photodetector one, the photodetector two and the photodetector three are recorded as background signals respectively 、 and , the to-be-detected vial one, the to-be-detected vial two and the to-be-detected vial three are placed in the detection area, and the level values of the photodetector one, the photodetector two and the photodetector three are recorded as detection signals respectively 、 and , the actual oxygen content in the bottle corresponds to the level value , i represents which group of detection vial;

[0024] Step 7, compare the voltage value V measured by each channel with the voltage value Vb measured by the standard gas, and the oxygen concentration in the to-be-detected vial under the current condition can be obtained;

[0025] Step 8, the oxygen concentration in the to-be-detected vial obtained above is transmitted to the computer, the detection content threshold Vth is set, if V>Vth, it is judged as qualified, if V

[0026] In summary, the present application includes at least one of the following beneficial effects: compared with the system for measuring the oxygen concentration in the penicillin bottle based on the 2f signal, the present application introduces a reference gas cell, demodulates the absorption signal obtained by detection, and obtains the 1f signal which is fed back to the laser by the PID algorithm to realize the locking of the laser frequency at the absorption peak position. The oxygen concentration and the voltage value at the absorption peak satisfy a linear relationship, so that only the level signal received by the detector needs to be measured to directly obtain the oxygen concentration under the current condition, and the detection rate is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A schematic diagram of a measuring device for rapidly detecting the oxygen content of a penicillin bottle according to the present application is provided.

[0028] Figure 2 A direct absorption signal diagram when the laser frequency is not locked for 2 hours according to the present application is provided.

[0029] Figure 3 A direct absorption signal diagram after the laser frequency is locked for 2 hours according to the present application is provided.

[0030] Figure 4 A diagram of the relationship between the oxygen standard gas and the detector level signal after the laser frequency is locked according to the present application is provided.

[0031] Figure 5 A standard gas concentration corresponding diagram according to the present application is provided.

[0032] In the drawings, the components represented by each reference numeral are listed as follows:

[0033] 1-external optical system, 11-DFB laser, 12-beam splitter, 13-plane mirror, 14-fiber coupler beam splitter, 2-frequency locking system, 21-reference gas cell, 22-optical detector four, 23-signal acquisition and feedback control system, 3-first detection system, 31-penicillin bottle to be detected, 32-optical detector one, 4-second detection system, 41-penicillin bottle to be detected, 42-optical detector two, 5-third detection system, 51-penicillin bottle to be detected, 52-optical detector three, 6-computer. DETAILED DESCRIPTION

[0034] The following will be described in detail in combination with the accompanying drawings Figures 1-5 The present application will be further described in detail.

[0035] An embodiment provided by the present application is as follows: Figure 1As shown, a kind of measuring device for quickly detecting oxygen content of penicillin bottle, including external optical path system 1, frequency locking system 2, first detection system 3, second detection system 4, third detection system 5 and computer 6, external optical path system 1 includes DFB laser 11, beam splitter 12, plane mirror 13 and fiber coupling beam splitter 14, DFB laser 11 is connected with driving current source and temperature control to realize the continuous tuning of laser wavelength, wherein the center wavelength is 760nm, and the tunable range is 2nm.DFB laser 11 output laser superimposed with sinusoidal modulation signal, laser is transmitted to frequency locking system 2 after beam splitter 12 and plane mirror 13.Reference gas cell 21, photodetector four 22 and signal acquisition and feedback control system 23 are included in frequency locking system 2, reference gas cell 21 is filled with oxygen, signal acquisition and feedback control system 23 includes function generation module, digital demodulation module, PID module and the like, function generation module can generate triangular wave and sine wave for scanning laser frequency and modulating the current of DFB laser 11, digital demodulation module is used to generate 1f signal, and PID module is superimposed with sine signal after processing 1f signal to realize the locking of laser frequency.DFB laser 11 is transmitted to reference gas cell 21 in sequence through beam splitter 12 and plane mirror 13, laser is incident to photodetector four 22 after passing through reference gas cell 21, the output end of photodetector four 22 is connected with signal acquisition and feedback control system 23, and the action path of laser in frequency locking system 2 is as follows: laser first passes through reference gas cell 21, then is received by photodetector four 22 and enters signal acquisition and feedback control system 23, so as to realize the locking of laser frequency.

[0036] DFB laser 11 can be coupled to fiber coupling beam splitter 14 through beam splitter 12, beam splitter 12 divides laser into two paths according to the ratio of 1:9, and is transmitted to frequency locking system 2 and fiber coupling beam splitter 14 respectively, fiber coupling beam splitter 14 can change the transmission of laser from space to fiber, and also can realize three-way transmission of light beam, therefore, fiber coupling beam splitter 14 can transmit laser to first detection system 3, second detection system 4 and third detection system 5 in three parts;First detection system 3 includes to be detected penicillin bottle one 31 and photodetector one 32, second detection system 4 includes to be detected penicillin bottle two 41 and photodetector two 42, and third detection system 5 includes to be detected penicillin bottle three 51 and photodetector three 52, photodetector four 22, photodetector one 32, photodetector two 42 and photodetector three 52 all include transimpedance amplification circuit and low-pass filter, and the transimpedance amplification circuit is used for amplification processing of electrical signal, and the low-pass filter is used for filtering the signal after amplification.Photodetector one 32, photodetector two 42 and photodetector three 52 convert the received optical signal into electrical signal and transmit to computer 6 to realize signal processing and recording.

[0037] The embodiment of the present application also provides a detection method for quickly detecting oxygen content of a vial, which is based on Figure 1 The measuring device for quickly detecting oxygen content of a vial is realized, which mainly includes the following steps:

[0038] Step 1, turn on the power supply of the DFB laser 11, refer to the oxygen resonance absorption line in the HTRAN database, adjust the driving current and temperature of the DFB laser 11, monitor the laser output frequency through the wavelength meter, and make the DFB laser 11 work near the oxygen resonance absorption line.

[0039] Step 2, open the function generating module in the signal acquisition and feedback control system 23, superimpose the triangular wave voltage output by the function generating module to the driving current of the DFB laser 11, realize small-range scanning of the laser frequency, observe the level change of the photodetector four 22 in the reference frequency locking system 2 to obtain the corresponding absorption spectrum line, and extract the current value at the absorption peak.

[0040] Step 3, the signal acquisition and feedback control system 23 performs peak searching on the absorption spectrum line and obtains the current value corresponding to the peak value, closes the triangular wave scanning voltage, superimposes a sinusoidal wave near the absorption peak current, and realizes sinusoidal modulation of the absorption peak current. The modulated laser passes through the reference gas cell and interacts with the oxygen molecules and is received by the photodetector four 22 and converted into an electrical signal. The signal is demodulated into a 1f signal, that is, a frequency discrimination signal is obtained;

[0041] The modulation frequency is , the phase modulation amplitude is β, and the modulation phase is

[0042]

[0043] Then the optical frequency and the modulated light field are

[0044]

[0045]

[0046] The latter term of the above formula is the Fourier expansion of the frequency-modulated light field, is the nth-order Bessel function

[0047] When the laser transmits through a sink of a certain length L, the light intensity transmittance obeys the Beer-Lambert law

[0048]

[0049] In the formula, is called optical depth, and since the intrinsic absorption line type is mostly Lorentz line type, the optical depth can be written as

[0050]

[0051] In the formula, , . To detect the center frequency of light, a Fourier expansion with respect to the optical depth z yields the following:

[0052]

[0053] coefficients in the formula

[0054]

[0055] An approximate expansion near the absorption peak yields the following results:

[0056]

[0057]

[0058]

[0059] when At that time, the permeability of the absorption cell can be approximately...

[0060]

[0061] The first-order component of the modulation spectrum is proportional to the frequency deviation.

[0062]

[0063] By obtaining the frequency discrimination signal Integrate with a PID feedback control system to optimize the PID proportional coefficient ( ), Integral parameters ( ) and differential parameters ( This achieves long-term locking of the laser frequency. The output of the PID controller is as follows:

[0064]

[0065] Figure 2 and Figure 3 The figures show the voltage changes when the laser frequency is unlocked and when it is locked, respectively, for the direct absorption of the signal.

[0066] Step 4: Measure the relationship between the voltage value of the oxygen standard gas and the oxygen concentration after laser locking. The experimental results are as follows: Figure 4 and Figure 5 As shown.

[0067] Step 5: Evacuate the vial to be tested to near vacuum and place it in the testing area, then record the current voltage level of the photodetector (level 32). The level value is the background signal of the light loss of the bottle wall of the vial, and then the sample vial to be detected is placed in the detection area to record the corresponding level value The actual voltage value of the oxygen in the vial The voltage value is compared with the voltage value obtained by using the standard gas, and the content of the oxygen in the vial 31 to be detected is obtained.

[0068] Step 6, the concentration of the oxygen in the vials placed in the other two channels is measured by repeating step 5.

[0069] The above are the preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A measuring device for rapid detection of oxygen content in a vial, comprising an external light path system (1), a first detection system (3), a second detection system (4), a third detection system (5) and a computer (6), characterized in that: The external light path system (1) comprises a DFB laser (11), a beam splitter (12), a plane mirror (13) and a fiber coupling beam splitter (14), the DFB laser (11) is optically connected with a frequency locking system (2) through the beam splitter (12) and the plane mirror (13) in sequence; The DFB laser (11) is coupled with the fiber coupling beam splitter (14) through the beam splitter (12), the fiber coupling beam splitter (14) is optically connected with a first detection system (3), a second detection system (4) and a third detection system (5) respectively, and the computer (6) is electrically connected with the first detection system (3), the second detection system (4) and the third detection system (5) respectively; The frequency locking system (2) comprises a reference gas cell (21), a photoelectric detector four (22) and a signal acquisition and feedback control system (23), the DFB laser (11) is optically connected with the reference gas cell (21) through the beam splitter (12) and the plane mirror (13) in sequence, laser is transmitted to the photoelectric detector four (22) by the reference gas cell (21), and an output end of the photoelectric detector four (22) is connected with the signal acquisition and feedback control system (23); The signal acquisition and feedback control system (23) comprises a function generating module, a digital demodulation module and a PID module; The first detection system (3) comprises a to-be-detected penicillin bottle one (31) and a photoelectric detector one (32), the second detection system (4) comprises a to-be-detected penicillin bottle two (41) and a photoelectric detector two (42), the third detection system (5) comprises a to-be-detected penicillin bottle three (51) and a photoelectric detector three (52), and the photoelectric detector four (22), the photoelectric detector one (32), the photoelectric detector two (42) and the photoelectric detector three (52) all comprise a transimpedance amplification circuit and a low-pass filter.

2. The measuring device for quickly detecting the oxygen content of a vial according to claim 1, characterized in that: The DFB laser (11) is connected with a driving current source and a temperature control.

3. A detection method for rapidly detecting oxygen content of a penicillin bottle according to any one of claims 1-2, comprising the following steps: Step 1, turn on the power supply of the DFB laser (11), adjust the output current and temperature, so that the light frequency is near the oxygen absorption line; the signal acquisition and feedback control system (23) outputs a triangular wave signal and superimposes it on the DFB laser (11), observes the absorption spectrum collected by the photoelectric detector four (22), and extracts the current value at the absorption peak; Step 2, remove the triangular wave scanning signal, adjust the laser current to the absorption peak, and the signal acquisition and feedback control system (23) outputs a sinusoidal wave and superimposes it on the DFB laser (11); Step 3, the signal acquisition and feedback control system (23) performs differential operation on the modulation signal with absorption characteristics, starts the PID function, realizes dynamic feedback of the absorption peak current, and feeds back the signal to the current drive of the laser, so as to realize frequency locking of the laser at the reference gas absorption peak position. Step 4, put oxygen standard gas into the detection area, measure the four (22) level value Vb of the photodetector under the current condition, repeat the measurement of different concentrations of oxygen standard gas, obtain the relationship between the corresponding standard gas oxygen concentration and the photodetector Vb, and linearly fit it; Step 5, couple the frequency-locked laser into the fiber-coupled beam splitter (14), and distribute the laser to the first detection system (3), the second detection system (4) and the third detection system (5) respectively; Step 6, adjust the height of the optical fiber output head according to the height of the first vial (31), the second vial (41) and the third vial (51) to be detected so that it can pass through the bottle, perform vacuum treatment on the empty sample bottle and place it in the detection area, and record the current level values of the photodetector one (32), the photodetector two (42) and the photodetector three (52) as background signals , and , place the first vial (31), the second vial (41) and the third vial (51) to be detected in the detection area, and record the current level values of the photodetector one (32), the photodetector two (42) and the photodetector three (52) as detection signals , and , the level value corresponding to the actual oxygen content in the bottle is , i represents which group of vials is detected; Step 7, compare the voltage value V measured by each measurement with the voltage value Vb measured by the standard gas, and the concentration of the oxygen in the detection vial under the current condition can be obtained; Step 8, transmit the oxygen concentration in the detection vial obtained above to the computer, set the detection content threshold Vth, if V>Vth, it is judged as qualified, if VVth, it is judged as unqualified.

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